Airway management in a case of tongue flap division surgery: a case report.

SUMMARY
This article sums up successful airway management in an 18-year-old male presented for tongue flap division surgery constructed before for a palatal fistula in our hospital. After induction of general anaesthesia, we performed laryngoscopy with right molar approach using miller straight blade, intubated from right side of flap and throat packing done using left molar approach. Tongue flap was divided without any ties and hemostasis checked.


Introduction
Tongue flaps are an accepted method of treating defects of the palate.The tongue flap techniqueis based on the use of a flap constructed from the dorsum of the tongue to close a defect in the palate 1 . These airways arereadily managedfor the initialflap construction surgery using nasal intubation 2 . Securing the airway for the tongue flap division surgeryis more challenging .We report successful airway management for tongue flap division surgery who waspreviously operatedfor palatal fistula.

Case report
An 18-year-old and 58kg weight male presented for division of tongue flap (Fig 1)constructed 3 weeks ago for a palatal fistula. Past surgical history was significant for bilateral cleft lip and palate repair in childhood and maxillarydistraction after LeFort osteotomy 1year back. Past medical history was unremarkable.
Allthe routine investigations like hematologic, chest x-ray and ECG were normal. On examination of the airway, mouth opening was restricted to 3 fingerbreadths due to the tongue flap. Uvula and posterior pharyngealwall couldn't be visualized.
On the day of surgery, after confirming adequate starvation and informed consent, patient was taken inside the operation theatre and monitors -cardioscope, pulse oximeter, non-invasive blood pressure cuff and capnometer were attached.Anaesthesia was induced with propofol 120 mg i.v. After confirming adequate mask ventilation, pancuronium 4mg was given. Midazolam 1.5mg and pentazocine 18mg i.v. were givenfor sedation and analgesia. Then both lungs were ventilated with O 2 and N 2 O(50:50) in a close circuit for 3minutes. Laryngoscopy was performedwith right molar approach using Miller no.3 blade (Fig 2) and trachea was intubated usingno.9 PVC cuffed endotrachealtubefrom right side of flap. Correct placement of tracheal tube was confirmed by bilateralchest auscultation and capnography. Throat packing was done us- ing left molar approach (Fig 3). Flap was divided withoutany ties and surgeryaccomplished .Both ends were sutured and hemostasisconfirmed. Throughoutthe surgery, patient's vitals remained within normalrange.After completion of surgery,neuromuscularblockade was reversed with neostigmine 3mg and glycopyrrolate 0.4mg i.v. Before extubation, both tongue and palatal sites of attachment weresprayed with one puff each of 10% lidocaine. Trachea was extubated smoothly and patient was observed for 10minutes before shifting to postoperative recovery room.

Discussion
Tongue flaps are an accepted method of treating palataldefects. Tongue flap surgery for cleft palate repair involves two separate operations. In the first , a tongue flap is created to close the palatal defect 1 and in the second, the flap is divided, freeing the tongue from palate.Airway management for the second operation is complicated by the flap between the tongue and the palate.
Tongue flap may be divided under local anaesthesia followed by induction of generalanaesthesia. In their letter to the editor, Sherry Peter et al 3 have suggested division of tongue flap under local anaesthesia without vasoconstrictors before general anaesthesia. They tied two silk threads towards the tongue end of the flap and flap is divided between them. This technique prevents bleeding.If bleedingoccurs, it is immediately cauterized with bipolar cautery. After the flap was divided, they proceeded withconventional induction of generalanaesthesia and orotracheal intubation. Julio Hochberg et al 4 accomplished inhalational induction with 60% N 2 O, 40% O 2 and 2-2.5% halothane.Red rubber catheters were introduced through both nostrils to the pharynx asairways tofacilitate spontaneous ventilation with a high flow of gases.They also ligated the base of the tongue pedicle doubly, using heavy silk. The pedicle was then cut between two ties.
However dividing the flap under local anaesthesia requires patient's cooperation.There may be bleeding into the airway. To avoid the problems ,we decided to secure the airway before the division of flap to preclude the possibility of bleeding and aspiration into an unsecured airway.
For the flap division procedure in one patient, Naveen Eipe et al 5 used ketamine 50 mg i.v. for sedation, glycopyrrolate 0.2 mg i.v. to control secretions. The surgeons inserted a mouth gag and proceeded to divide theflap with the patientbreathing spontaneously. After successful flap division, the patient was anaes- In the second patient ,they used intravenous ketamine to induce general anaesthesia followed by ventilation with O 2 : N 2 O (50:50) and halothane 1% inhalation.They performedan initiallaryngoscopy with the head turned to right and laryngoscope blade carefully inserted to the left of the flap usingretromolar approach.After confirming laryngealvisualization, intravenous succinylcholine 50mg was administered and direct laryngoscopy performed. An orotracheal tube was passed to the left of the flap. Here it should be emphasized that after any palatoplasty, it is advisable to avoid nasal intubation as this may damage or disrupt the recently constructed flap 6 .
The molar approach reduces the distance from the patient's teeth to the larynx and prevents intrusion of maxillary structures into the line of view.Aright molar approach has an additionaladvantage thatthe bulging of tongue over the blade is prevented unlike the midline approach. In our case, we decided to use a right molar approach with a straight blade. The breadth of straight Miller no.3 blade is lesser than the curved Macintosh no.3 blade (Fig 4). This minimized the trauma to the tongue flap and provided adequate space for intubation. The drawbackof left molar approach by causing bulging of the tongue over theblade and obscuring the glottic view was overcome by using right molar approach. We chose to induce general anaesthesia be- fore division of the flap for airway protection and for patient, surgeons and anaesthesiologists' comfort. Laryngoscopy for packing the throat was done using left molar approach as the endotrachealtube occupied right sided space.
In our opinion, any approachcan be used though Miller straight blade to be preferred over Macintosh curved blade in tongue flap division surgery for securingairway. The choice depends on anaesthesiologists' expertise. However , orotracheal intubation using a fibreoptic scope remains the preferred option in such cases. But it may not be available freely in developing countries like India. So familiarity with use of different laryngoscopic blades and approaches is essential for the anaesthesiologists.